Magnetically-actuated variable-length connecting rod devices and methods for controlling the same

ABSTRACT

A method can include: providing a connecting rod device disposed inside of a cylinder of an engine, the connecting rod device coupled to a piston head and extending therefrom, the connecting rod device including a variable-length connecting rod and a connecting rod magnet movably coupled to the variable-length connecting rod; and adjusting a length of the connecting rod by supplying a current to pass through a solenoid wrapped around the cylinder, the current passing through the solenoid generating a magnetic field which activates the connecting rod magnet. The activation of the connecting rod magnet can cause an increase or a decrease of the length of the connecting rod.

TECHNICAL FIELD

The present disclosure relates generally to connecting rod devices, andmore particularly, to magnetically-actuated variable-length connectingrod devices and methods for controlling the same.

BACKGROUND

A connecting rod is generally known as a rigid member that provides themechanical linkage between a piston of an engine, particularly areciprocating engine such as an internal combustion engine, and a crankor crankshaft. The connecting rod functions as a lever arm by pushingand pulling the piston into and out of the cylinder, and converts thelinear up-and-down movement of the piston into rotation of thecrankshaft. This motion is then passed on to a series of devices capableof providing power to the machine, e.g., vehicle, in which the engine isequipped.

A common measure of engine power, which is dependent upon the connectingrod, is compression ratio, defined as the ratio between the swept volumeof a cylinder with the piston at bottom dead center (BDC) and the sweptvolume of the cylinder with the piston at top dead center (TDC). Putmore simply, compression ratio can refer to the ratio of maximum volumeto minimum volume in the cylinder. When the connecting rod has a fixedlength, the engine will have a fixed displacement and compression ratio,as the maximum and minimum volume in the cylinder are constant.

A fixed compression ratio, problematically, can result in missedperformance optimization. For instance, under low engine loads, such asidling, a higher compression ratio can yield improved fuel economy.Meanwhile, under high engine loads, such as a large power request fromthe driver, a lower compression ratio, combined with increased boost,can yield improved power.

SUMMARY

The present disclosure provides a variable-length connecting rod devicecapable of dynamically changing engine displacement and compressionratio to improve overall vehicle efficiency by matching compressionratios to appropriate engine load conditions. The variable-lengthconnecting rod device, as described herein, can vary the length of theconnecting rod during operation of the engine to increase or decreasethe engine's compression ratio in response to high or low engine loads,thereby optimizing engine performance Furthermore, the variable-lengthconnecting rod device, as described herein, can adjust the length of theconnecting rod using magnetic forces, thereby eliminating unnecessaryauxiliary components, such as motors, simplifying the connecting roddesign, and reducing overall packaging size.

According to embodiments of the present disclosure, a method caninclude: providing a connecting rod device disposed inside of a cylinderof an engine, the connecting rod device coupled to a piston head andextending therefrom, the connecting rod device including avariable-length connecting rod and a connecting rod magnet movablycoupled to the variable-length connecting rod; and adjusting a length ofthe connecting rod by supplying a current to pass through a solenoidwrapped around the cylinder, the current passing through the solenoidgenerating a magnetic field which activates the connecting rod magnet.The activation of the connecting rod magnet can cause an increase or adecrease of the length of the connecting rod.

Furthermore, according to embodiments of the present disclosure, amethod can include: providing a connecting rod device disposed inside ofa cylinder of an engine, the connecting rod device coupled to a pistonhead and extending therefrom, the connecting rod device including avariable-length connecting rod including a female component with ahollow body and a male component movably disposed at least partiallyinside of the female component, the male component configured to becoupled to a crankshaft of the engine, and the connecting rod devicefurther including a connecting rod magnet movably coupled to the femalecomponent; and supplying a current to pass through a solenoid wrappedaround the cylinder, the current passing through the solenoid generatinga magnetic field which activates the connecting rod magnet. Theactivation of the connecting rod magnet can cause the connecting roddevice to transition from a coupled state, in which the male componentis held in unison with the female component, to a de-coupled state, inwhich movement of the connecting rod magnet causes a release of the malecomponent, allowing the male component to move independent of the femalecomponent along an axis of the connecting rod.

Furthermore, according to embodiments of the present disclosure, amethod can include: providing a connecting rod device disposed inside ofa cylinder of an engine, the connecting rod device coupled to a pistonhead via a piston coupling mechanism disposed at least partially insideof the piston head, the connecting rod device including avariable-length connecting rod, the piston coupling mechanism includingfirst and second piston-cylinder coupling pads movably disposed atopposite axial ends of the piston coupling mechanism, respectively, anda piston coupling mechanism magnet movably disposed at least partiallybetween the first and second piston-cylinder coupling pads; andsupplying a current to pass through a solenoid wrapped around thecylinder, the current passing through the solenoid generating a magneticfield which activates the piston coupling mechanism magnet. Theactivation of the piston coupling mechanism magnet can cause the pistoncoupling mechanism to transition from a retracted state, in which thefirst and second piston-cylinder coupling pads are positioned inside ofan outer wall of the piston head, to an extended state, in whichmovement of the piston coupling mechanism magnet causes the first andsecond piston-cylinder coupling pads to move along an axis of the pistoncoupling mechanism outside of the outer wall of the piston head, suchthat the first and second piston-cylinder coupling pads abut an innersurface of the cylinder to hold the piston head in place inside of thecylinder.

BRIEF DESCRIPTION OF THE DRAWINGS

The embodiments herein may be better understood by referring to thefollowing description in conjunction with the accompanying drawings inwhich like reference numerals indicate identically or functionallysimilar elements, of which:

FIGS. 1A and 1B are views of an exemplary magnetically-actuated pistonand connecting rod device with a variable-length connecting rod;

FIG. 2 is a select-component view of the magnetically-actuated pistonand connecting rod device of FIGS. 1A and 1B;

FIGS. 3A-3D are views of the magnetically-actuated piston and connectingrod device of FIGS. 1A and 1B when no current is applied to a solenoidwrapped around a cylinder of an engine;

FIGS. 4A-4D are views of the magnetically-actuated piston and connectingrod device of FIGS. 1A and 1B when a current passes through the solenoidwrapped around the cylinder of the engine;

FIGS. 5A-C are operational views showing an exemplary process oflengthening the connecting rod of the magnetically-actuated piston andconnecting rod device of FIGS. 1A and 1B;

FIGS. 6A-C are operational views showing an exemplary process ofshortening the connecting rod of the magnetically-actuated piston andconnecting rod device of FIGS. 1A and 1B;

FIGS. 7A and 7B are views of an exemplary piston coupling mechanism whenno current is applied to the solenoid wrapped around the cylinder of theengine;

FIGS. 8A and 8B are views of the piston coupling mechanism of FIGS. 7Aand 7B when a current passes through the solenoid wrapped around thecylinder of the engine;

FIGS. 9A and 9B are views of another exemplary magnetically-actuatedpiston and connecting rod device with a variable-length connecting rod;

FIGS. 10A-10C are views of the magnetically-actuated piston andconnecting rod device of FIGS. 9A and 9B when no current is applied tothe solenoid wrapped around the cylinder of the engine;

FIGS. 11A-11C are views of the magnetically-actuated piston andconnecting rod device of FIGS. 9A and 9B when a current passes throughthe solenoid wrapped around the cylinder of the engine;

FIG. 12 is a flowchart illustrating an exemplary procedure forcontrolling operation of a magnetically-actuated piston and connectingrod device;

FIG. 13 is the flowchart of FIG. 12 showing an exemplary procedure forlengthening the connecting rod of the magnetically-actuated piston andconnecting rod device;

FIG. 14 is the flowchart of FIG. 12 showing an exemplary procedure forshortening the connecting rod of the magnetically-actuated piston andconnecting rod device;

FIG. 15 is the flowchart of FIG. 12 showing an exemplary procedure forlengthening the connecting rod of the magnetically-actuated piston andconnecting rod device to achieve a torque increase; and

FIG. 16 is the flowchart of FIG. 12 showing an exemplary procedure forshortening the connecting rod of the magnetically-actuated piston andconnecting rod device after lengthening the connecting rod for improvedtorque.

It should be understood that the above-referenced drawings are notnecessarily to scale, presenting a somewhat simplified representation ofvarious preferred features illustrative of the basic principles of thedisclosure. The specific design features of the present disclosure,including, for example, specific dimensions, orientations, locations,and shapes, will be determined in part by the particular intendedapplication and use environment.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Hereinafter, embodiments of the present disclosure will be described indetail with reference to the accompanying drawings. As those skilled inthe art would realize, the described embodiments may be modified invarious different ways, all without departing from the spirit or scopeof the present disclosure. Further, throughout the specification, likereference numerals refer to like elements.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of the disclosure.As used herein, the singular forms “a,” “an,” and “the” are intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. It will be further understood that the terms “comprises”and/or “comprising,” when used in this specification, specify thepresence of stated features, integers, steps, operations, elements,and/or components, but do not preclude the presence or addition of oneor more other features, integers, steps, operations, elements,components, and/or groups thereof. As used herein, the term “and/or”includes any and all combinations of one or more of the associatedlisted items.

It is understood that the term “vehicle” or “vehicular” or other similarterm as used herein is inclusive of motor vehicles in general such aspassenger automobiles including sports utility vehicles (SUV), buses,trucks, various commercial vehicles, watercraft including a variety ofboats and ships, aircraft, and the like, and includes hybrid vehicles,electric vehicles, plug-in hybrid electric vehicles, hydrogen-poweredvehicles and other alternative fuel vehicles (e.g., fuels derived fromresources other than petroleum). As referred to herein, a hybrid vehicleis a vehicle that has two or more sources of power, for example bothgasoline-powered and electric-powered vehicles.

Additionally, it is understood that one or more of the below methods, oraspects thereof, may be executed by at least one control unit, orelectronic control unit (ECU). The term “control unit” may refer to ahardware device that includes a memory and a processor. The memory isconfigured to store program instructions, and the processor isspecifically programmed to execute the program instructions to performone or more processes which are described further below. The controlunit may control operation of units, modules, parts, devices, or thelike, as described herein. Moreover, it is understood that the belowmethods may be executed by an apparatus comprising the control unit inconjunction with one or more other components, as would be appreciatedby a person of ordinary skill in the art.

Furthermore, the control unit of the present disclosure may be embodiedas non-transitory computer readable media containing executable programinstructions executed by a processor, controller or the like. Examplesof the computer readable mediums include, but are not limited to, ROM,RAM, compact disc (CD)-ROMs, magnetic tapes, floppy disks, flash drives,smart cards and optical data storage devices. The computer readablerecording medium can also be distributed throughout a computer networkso that the program instructions are stored and executed in adistributed fashion, e.g., by a telematics server or a Controller AreaNetwork (CAN).

Referring now to embodiments of the present disclosure, the disclosedvariable-length connecting rod device is capable of dynamically changingengine displacement and compression ratio. The connecting rod deviceincludes one or more magnets which can be actuated in the presence of amagnetic field to lengthen or shorten the connecting rod. The magneticfield can be activated at specific times during operation of the engineto adjust the length of the connecting rod such that the resultantcompression ratios are matched to appropriate engine load conditions,thus improving overall engine load conditions and performance

FIGS. 1A and 1B are views of an exemplary magnetically-actuated pistonand connecting rod device with a variable-length connecting rod. Asshown in FIGS. 1A and 1B, the magnetically-actuated piston andconnecting rod device 100 can include a piston head 110 coupled to aconnecting rod device extending therefrom. The piston head 110 can becylindrically shaped in some embodiments, but the shape of the pistonhead 110 is not limited thereto. The piston head 110 can be disposedinside of a cylinder 400 of an engine (not shown), particularly areciprocating engine such as an internal combustion engine, and cantravel vertically (depending on orientation) inside of the cylinder 400.While only a single magnetically-actuated piston and connecting roddevice 100 is shown in FIGS. 1A and 1B and throughout the remainingfigures, a magnetically-actuated piston and connecting rod device 100,as described in detail herein, can be disposed in each cylinder 400 ofthe engine.

The magnetically-actuated piston and connecting rod device 100 canfurther include a connecting rod device coupled to the piston head 110and extending therefrom, as mentioned above. The connecting rod devicecan include a variable-length connecting rod with a male component 120and a female component 130. The female component 130 can be formed withan at least partially hollow body. The male component 120 can be formedsuch that at least a portion thereof can be movably inserted into thehollow body of the female component 130.

A distal end of the male component 120 (closest to the piston head 110)can be inserted into the female component 130, and a proximal end of themale component 120 (furthest from the piston head 110) can be formedwith a circular opening configured to receive a crankshaft (not shown)of the engine 400. Meanwhile, a proximal end of the female component 130can include an opening configured to receive the distal end of the malecomponent 120, and a distal end of the female component can be coupledto the piston head 110 via the piston coupling mechanism 200.

Each of the male component 120 and female component 130 can becylindrically shaped in some embodiments, but the respective shapes ofthe male component 120 and female component 130 are not limited thereto.Under certain circumstances described in greater detail below, the malecomponent 120 can move in and out of the female component 130 along theaxis (longitudinal axis) of the connecting rod, thereby varying thelength of the connecting rod. The female component 130, meanwhile, canremain positionally fixed with respect to the connecting rod device byvirtue of its connection to the piston head 110.

The connecting rod device can further include first and secondmale-female coupling pads 140 disposed on opposite sides of the femalecomponent 130. Under certain circumstances described in greater detailbelow, the first and second male-female coupling pads 140 can moveperpendicular to the axis of the connecting rod. The respective innerwalls of the first and second male-female coupling pads 140 can becylindrically shaped so as to conform to the shape of the male component120. Thus, the first and second male-female coupling pads 140 can holdthe male component 120 in unison with the female component 130 byapplying opposing forces on the male component 120 in a directionperpendicular to the axis of the connecting rod. That is, the first andsecond male-female coupling pads 140 can push against each other withthe male component 120 therebetween to hold the male component 120 inplace inside of the female component 130.

In greater detail, FIG. 2 is a select-component view of themagnetically-actuated piston and connecting rod device 100. Fordemonstration purposes, the first male-female coupling pad 140, firstlinkage arm 171, and second joint 163 are removed from view. As shown inFIG. 2, the respective inner walls of the first and second male-femalecoupling pads 140 can be formed with a curvature corresponding to theouter shape of the male component 120. This can allow the first andsecond male-female coupling pads 140 to rigidly hold the male component120 when no magnetic field is present. The first and second male-femalecoupling pads 140 can hold the male component 120 within the femalecomponent 130 at multiple possible positions, allowing for precisecompression ratio adjustment.

Referring again to FIGS. 1A and 1B, the connecting rod device canfurther include a connecting rod magnet 150, which is a magnet coupledto the female component 130 of the variable-length connecting rod. Insome embodiments, the connecting rod magnet 150 can be disposed on oraround a portion of the body of the female component 130, and shaped ina manner corresponding to the shape of the female component 130 (e.g.,cylindrically shaped). As such, the connecting rod magnet 150 can beconfigured to move over the portion of the body of the female component130 in response to a magnetic field proximate to the cylinder 400 of theengine along the axis of the connecting rod. Particularly, theconnecting rod magnet 150 can move in a first direction in response to amagnetic field proximate to the cylinder 400 and in a second, oppositedirection in response to deactivation of the magnetic field proximate tothe cylinder 400.

Disposed on opposite axial ends of the connecting rod magnet 150 can bea first spring 151 and a second spring 152. The first and second springs151, 152 can maintain the connecting rod magnet 150 in a default orcentered position when no magnetic field proximate to the cylinder 400is present. However, when a magnetic field proximate to the cylinder 400is present, the first spring 151 which is located proximal (i.e., closerto the crankshaft) of the connecting rod magnet 150 can compress due toproximal movement of the connecting rod magnet 150 along the axis of theconnecting rod. Axial movement of the connecting rod 150 in response toa magnetic field proximate to the cylinder 400 will be described ingreater detail below.

The connecting rod device can further include a series of componentsconnecting the connecting rod magnet 150 to the first and secondmale-female coupling pads 140. For starters, a plurality of joints 161,162, and 163 can extend through respective portions of the connectingrod magnet 150 and the first and second male-female coupling pads 140.The plurality of joints 161, 162, and 163 can extend in a directionperpendicular to the axis of the connecting rod. In particular, as shownin FIGS. 1A and 1B, a first joint 162 can extend through a portion ofthe first male-female coupling pad 140, a second joint 163 can extendthrough a portion of the second male-female coupling pad 140, and athird joint 161 can extend through a portion of the connecting rodmagnet 150. By virtue of the joints 161, 162, and 163 being attached tothe first and second male-female coupling pads 140 and the connectingrod magnet 150, each of the joints 161, 162, and 163 can move in unisonwith the first and second male-female coupling pads 140 and theconnecting rod magnet 150, respectively.

The plurality of joints 161, 162, and 163 can be interconnected througha series of linkage arms 171 and 172. For example, a first linkage arm172 can adjoin the first joint 162, which extends through a portion ofthe first male-female coupling pad 140, to the third joint 161, whichextends through a portion of the connecting rod magnet 150, and a secondlinkage arm 171 can adjoin the second joint 163, which extends through aportion of the second male-female coupling pad 140, to the third joint161.

In some embodiments, the linkage arms 171 and 172 can be made of a rigidmaterial such that the linkage arms 171 and 172 do not bend in responseto axial movement of the connecting rod magnet 150. Because the linkagearms 171 and 172 adjoin the connecting rod magnet 150 to the first andsecond male-female coupling pads 140, the axial movement of theconnecting rod magnet 150, which necessarily causes movement of thelinkage arms 171 and 172 connected to the connecting rod magnet 150 byvirtue of the third joint 161, can produce a corresponding movement ofthe first and second male-female coupling pads 140.

Moreover, axial movement of the connecting rod magnet 150 can cause thelinkage arms 171 and 172 to move angularly, or rotate, thereby movingthe first and second male-female coupling pads 140 in a directionperpendicular to the axis of the connecting rod. Indeed, when theconnecting rod device is in the coupled state, the first and secondlinkage arms 171 and 172 can extend at a first angle with respect to theaxis of the connecting rod, and when the connecting rod device is in thede-coupled state, the first and second linkage arms 171 and 172 canextend at a second angle, different from the first angle, with respectto the axis of the connecting rod. The perpendicular movement of thefirst and second male-female coupling pads 140 can de-couple the firstand second male-female coupling pads 140 from the male component 120,or, in other words, release the male component 120, allowing the malecomponent 120 to move freely inside of the female component 130 alongthe axis of the connecting rod due to rotation of the crankshaft, asdescribed in greater detail below.

The connecting components can further include a guiding plate 180disposed between the linkage arms 171 and 172 and the first and secondmale-female coupling pads 140. The guiding plate 180 can be fixed to thefemale component 130 such that the guiding plate 180 does not move. Inaddition, the guiding plate 180 can be formed with a plurality ofopenings corresponding to the plurality of joints 161, 162, and 163,whereby each opening in the guiding plate can receive one of the joints161, 162, or 163. The guiding plate openings can be formed with a widthto accommodate the above-described movement of the plurality of joints161, 162, and 163. Particularly, the guiding plate openings whichreceive the first joint 162 and the second joint 163, respectively, canextend in a direction perpendicular to the axis of the connecting rod soas to accommodate the perpendicular movement of the first joint 162 andthe second joint 163 (as the first and second male-female coupling pads140 move perpendicularly), and similarly, the guiding plate openingwhich receives the third joint 161 can extend in a direction parallel tothe axis of the connecting rod so as to accommodate the axial movementof the third joint 161 (as the connecting rod magnet 150 moves along theaxis of the connecting rod).

In some embodiments, a first guiding plate 180 can be disposed on afirst side of (e.g., above) the first and second male-female couplingpads 140, and a second guiding plate 180 can be disposed on a second,opposite side of (e.g., below) the first and second male-female couplingpads 140. In such case, the second guiding plate 180 can be disposedbetween the second side of the first and second male-female couplingpads 140 and a second pair of linkage arms 171 and 172 whichinterconnect the plurality of joints 161, 162, and 163. The first pairof linkage arms 171 and 172 can attach to respective first end regions(e.g., top) of the joints 161, 162, and 163, while the second pair oflinkage arms 171 and 172 can attach to respective second, opposite endregions (e.g., bottom) of the joints 161, 162, and 163. In otherembodiments, the connecting rod device can utilize only a single guidingplate 180 and single set of linkage arms 171 and 172.

The magnetically-actuated piston and connecting rod device 100 canfurther include a piston coupling mechanism 200 disposed at leastpartially inside of the piston head 110 that couples the connecting roddevice to the piston head 110. The piston coupling mechanism 200 can bepositioned inside of the piston head 110, in the wrist pin cavity, forexample, extending longitudinally in a direction perpendicular to theaxis of the connecting rod.

In detail, FIGS. 7A and 7B are views of an exemplary piston couplingmechanism when a magnetic field proximate to the cylinder 400 isinactive (i.e., no current is applied to the solenoid 410), and FIGS. 8Aand 8B are views of the piston coupling mechanism when such magneticfield is active (i.e., current passes through the solenoid 410).Activation and deactivation of the magnetic field proximate to thecylinder 400 will be described in greater detail below.

As shown in FIGS. 7A, 7B, 8A, and 8B, the piston coupling mechanism 200can include first and second piston-cylinder coupling pads 210 movablydisposed at opposite axial ends of the piston coupling mechanism 200,respectively. The first and second piston-cylinder coupling pads 210 canbe configured to move along the axis of the piston coupling mechanism200 (perpendicular to the axis of the connecting rod) in oppositedirections of each other. In this regard, the piston head 110 can beformed with openings therein shaped to receive the first and secondpiston-cylinder coupling pads 210, respectively. In a neutral state, thefirst and second piston-cylinder coupling pads 210 can be positionedinside of an outer wall of the piston head 110; however, these openingspermit the first and second piston-cylinder coupling pads 210 to movealong the axis of the piston coupling mechanism 200 outside of the outerwall of the piston head 110 under certain circumstances described ingreater detail below.

The piston coupling mechanism 200 can further include a piston couplingmechanism magnet 220 movably disposed at least partially between thefirst and second piston-cylinder coupling pads 210. The piston couplingmechanism magnet 220 can be formed with an opening through which aguiding rod 230 extends perpendicular to the axis of the piston couplingmechanism 200. The guiding rod 230 can be attached at one end to a fixedbase member 240 and extend outwardly therefrom. A spring 221 can bedisposed on or around the guiding rod 230 between the piston couplingmechanism magnet 220 and the base member 240.

The guiding rod 230 can be configured to guide the movement of thepiston coupling mechanism magnet 220 in a direction perpendicular to theaxis of the piston coupling mechanism 200. In this regard, magneticforces resulting from a magnetic field proximate to the cylinder 400 canpush the piston coupling mechanism magnet 220 along the guiding rod 230toward the base member 240 in a direction perpendicular to the axis ofthe piston coupling mechanism 200. Such movement can compress the spring221. Upon deactivation of the magnetic field, the spring 221 candecompress causing the piston coupling mechanism magnet 220 to move inthe opposite direction perpendicular to the axis of the piston couplingmechanism 200, returning the piston coupling mechanism magnet 220 to itsdefault state.

The piston coupling mechanism 200 can further include linkage arms 251and 252. For example, a first linkage arm 251 can adjoin the pistoncoupling mechanism magnet 220 to the first piston-cylinder coupling pad210, and a second linkage arm 252 can adjoin the piston couplingmechanism magnet 220 to the second piston-cylinder coupling pad 210disposed at an opposite side of the piston coupling mechanism 200 as thefirst piston-cylinder coupling pad 210.

In some embodiments, the linkage arms 251 and 252 can be made of a rigidmaterial such that the linkage arms 251 and 252 do not bend in responseto movement of the piston coupling mechanism magnet 220. Because thelinkage arms 251 and 252 adjoin the piston coupling mechanism magnet 220to the first and second piston-cylinder coupling pads 210, the movementof the piston coupling mechanism magnet 220 in a direction perpendicularto the axis of the piston coupling mechanism 200, which necessarilycauses movement of the linkage arms 251 and 252, can produce acorresponding movement of the first and second piston-cylinder couplingpads 210.

Moreover, movement of the piston coupling mechanism magnet 220 in adirection perpendicular to the axis of the piston coupling mechanism 200can cause the linkage arms 251 and 252 to move angularly, or rotate,thereby moving the first and second piston-cylinder coupling pads 210along the axis of the piston coupling mechanism 200. Indeed, when thepiston coupling mechanism 200 is in the retracted state, the first andsecond linkage arms 251 and 252 can extend at a first angle with respectto the axis of the piston coupling mechanism 200, and when the pistoncoupling mechanism 200 is in the extended state, the first and secondlinkage arms 251 and 252 can extend at a second angle, different fromthe first angle, with respect to the axis of the piston couplingmechanism 200. The axial movement of the first and secondpiston-cylinder coupling pads 210 can move the coupling pads 210 throughthe openings formed in the piston head 110 outside of the piston head110, such that the first and second piston-cylinder coupling pads 210abut an inner surface of the cylinder 400 to immobilize or hold thepiston head 110 in place inside of the cylinder 400, as described ingreater detail below.

When the magnetic field causing movement of the piston couplingmechanism magnet 220 is deactivated, the spring 221 can decompress, thusreturning the piston coupling mechanism magnet 220 to its defaultposition. The return movement of the piston coupling mechanism magnet220 can retract the linkage arms 251 and 252 and pull the first andsecond piston-cylinder coupling pads 210 back to their retractedposition inside of the walls of the piston head 110. Thus, the pistoncoupling mechanism magnet 220 can be configured to move in a firstdirection in response to the magnetic field proximate to the cylinder400 and in a second, opposite direction in response to deactivation ofthe magnetic field.

Referring next to FIGS. 3A-3D and FIGS. 4A-4D, the operation of themagnetically-actuated piston and connecting rod device 100 can bedescribed. In detail, the connecting rod device can be configured totransition between a “coupled state” and a “de-coupled state,” asexplained below, in response to a magnetic field proximate to thecylinder 400 in which the magnetically-actuated piston and connectingrod device 100 is disposed. Also, the piston coupling mechanism 200 canbe configured to transition between a “retracted state” and an “extendedstate,” as explained below, in response to the magnetic field proximateto the cylinder 400 in which the magnetically-actuated piston andconnecting rod device 100 is disposed.

The magnetic field can be generated by wrapping a solenoid 410 (e.g.,see FIGS. 5A-C and 6A-C) around each cylinder 400 of the engine. When anelectric current is applied to the solenoid 410, such that the currentpasses through the coils of the solenoid 410, magnetic forces act downthe length of the cylinder 400, thereby generating a magnetic field. Themagnetic field can cause responsive movement of magnetic bodies withinthe magnetic field, such as the connecting rod magnet 150 or pistoncoupling mechanism magnet 220, due to attractive or repulsive magneticforces acting upon the bodies.

Referring first to FIGS. 3A-3D, which include a perspective view, a sideview, a top view, and a close-up perspective view, respectively, of themagnetically-actuated piston and connecting rod device 100, no currentis applied to the solenoid 410 which is wrapped around cylinder 400.Thus, in the example of FIGS. 3A-3D, the magnetic field proximate to thecylinder 400 may be inactive, resulting in the coupled state of theconnecting rod device and the retracted state of the piston couplingmechanism 200.

Here, the connecting rod magnet 150 can be held in a default or centeredposition by virtue of first and second springs 151 and 152. While theconnecting rod magnet 150 is centered, the first and second male-femalecoupling pads 140 can be withdrawn, i.e., positioned against the malecomponent 120, due to being connected to the connecting rod magnet 150via the plurality of joints 161, 162 and 163 and linkage arms 171 and172. In this position, the respective inner surfaces of the first andsecond male-female coupling pads 140 can abut the outer surface of themale component 120 on opposing sides thereof in order to hold the malecomponent 120 in place within the female component 130. The first andsecond male-female coupling pads 140 can apply counteracting forces onthe male component 120 in a direction perpendicular to the axis of theconnecting rod. Therefore, the male component 120 can be held in unisonwith the female component 130, and unable to move independently of thefemale component 130, in the coupled state of the connecting rod device.

Additionally, in the absence of the magnetic field proximate to thecylinder 400, the first and second piston-cylinder coupling pads 210 canbe retracted, or withdrawn, in the piston head 110. That is, the firstand second piston-cylinder coupling pads 210 can be positioned inside ofan outer wall of the piston head 110. In this position, the piston head110 is able to move freely within the cylinder 400 due to regularoperation of the engine.

Next, referring to FIGS. 4A-4D, which include a perspective view, a sideview, a top view, and a close-up perspective view, respectively, of themagnetically-actuated piston and connecting rod device 100, a currentpasses through the solenoid 410 wrapped around the cylinder 400, therebygenerating a magnetic field along the length of the cylinder 400. Thus,in the example of FIGS. 4A-4D, the magnetic field proximate to thecylinder 400 may be active, resulting in the de-coupled state of theconnecting rod device and the extended state of the piston couplingmechanism 200.

Here, the connecting rod magnet 150 can move down the length of thefemale component 130, that is, proximally (toward the male component120) along the axis of the connecting rod, in response to the generatedmagnetic field, thereby compressing the first spring 151 proximal of theconnecting rod magnet 150. Because the connecting rod magnet 150 isconnected to the first and second male-female coupling pads 140 via theplurality of joints 161, 162, and 163 and linkage arms 171 and 172, thefirst and second male-female coupling pads 140 can move outwardly fromthe male component 120, that is, perpendicular to the axis of theconnecting rod, thus separating from the male component 120. When thefirst and second male-female coupling pads 140 move in this manner, themale component 120 may no longer be rigidly held inside of the femalecomponent 130, causing a release of the male component 120, and ade-coupling of the male component 120 from the female component 130.This can “unlock” the male component 120 such that it is allowed to moveindependent of the female component 130 along the axis of the connectingrod due to the inertia of the normal crankshaft motion (rotation),thereby adjusting the effective length of the connecting rod. Thesprings 151 and 152 can return the connecting rod magnet 150 to itscentered, “default” position once the current applied to the solenoid410 stops.

Additionally, in response to the generated magnetic field, the pistoncoupling mechanism 200 can be activated, causing the piston couplingmechanism magnet 220 to move along the guiding rod 230 in a directionperpendicular to the piston coupling mechanism 200 (toward the fixedbase member 240). Such movement of the piston coupling mechanism magnet220 can cause the first and second piston-cylinder coupling pads 210 tomove along the axis of the piston coupling mechanism 200, so as toextend beyond the outer wall of the piston head 110, into the inner wallof the engine cylinder 400. This can hold the piston head 110, and thefemale component 130 attached thereto, in place inside of the cylinder400.

The de-coupling of the male component 120 and female component 130,along with the coupling of the piston head 110 to the inner wall of thecylinder 400, can enable the male component 120 to freely move withinthe female component 130 while current passes through the solenoid 410.This can allow for dynamic adjustment of connecting rod length based onthe point in time during the combustion cycle at which the currentactivates, as described in greater detail with reference to FIGS. 12-16.

Next, FIG. 5 is an operational view showing an exemplary process oflengthening the connecting rod of the magnetically-actuated piston andconnecting rod device 100, and FIGS. 6A-C is an operational view showingan exemplary process of shortening the connecting rod of themagnetically-actuated piston and connecting rod device 100. In each ofFIGS. 5A-C and 6A-C, the vertically extending helix line represents thesolenoid 410 wrapped around the cylinder 400. It is to be understoodthat the depictions of FIGS. 5A-C and 6A-C can replicated in eachcylinder 400 of the engine. As a result, the compression ratio of eachcylinder 400 can be individually adjusted.

Referring first to FIGS. 5A-C, the engine is operating, and the pistonhead 110 can be positioned at or near top dead center (TDC) at stage A.Here, no electric current is applied to the solenoid 410, and thus themagnetic field proximate to the cylinder 400 is inactive. That is, therecan be no magnetic field capable of moving magnetic bodies in themagnetically-actuated piston and connecting rod device 100. In suchcase, the connecting rod device can be in the coupled state, and thepiston coupling mechanism can be in the retracted state, as explainedabove.

At stage B, current can be passed through the solenoid 410, generating amagnetic field along the length of the cylinder 400. This can activatethe connecting rod magnet 150 of the connecting rod device and thepiston coupling mechanism magnet 220 of the piston coupling mechanism200 due to magnetic forces acting in the direction shown by the arrowsthrough solenoid 410. As explained above, activation of the connectingrod magnet 150, whereby the connecting rod magnet 150 moves proximallyalong the axis of the connecting rod, can transition the connecting roddevice to the de-coupled state in which the first and second male-femalecoupling pads 140 release the male component 120, allowing the malecomponent 120 to move independently of the female component 130.Similarly, activation of the piston coupling mechanism magnet 220,whereby the piston coupling mechanism magnet 220 moves down the lengthof the guiding rod 230 in a direction perpendicular to an axis of thepiston coupling mechanism 200 (toward the base member 240), cantransition the piston coupling mechanism 200 to the extended state.Here, the downward movement of the piston coupling mechanism magnet 220can cause the linkage arms 251 and 252 to push the first and secondpiston-cylinder coupling pads 210 along the axis of the piston couplingmechanism 200, in opposite directions, outside of an outer wall of thepiston head 110, such that the first and second piston-cylinder couplingpads 210 abut an inner surface of the cylinder 400 to immobilize or holdthe piston head 110 in place inside of the cylinder 400. Consequently,inertia due to the regular rotational motion of the crankshaft can pullon the male component 120, causing the male component 120 to slidevertically out of the female component 130, while the female component130 is prevented from moving vertically due to its connection to thefixed piston head 110.

At stage C, the current applied to the solenoid 410 can be deactivated.In response, the connecting rod device can transition back to thecoupled state, in which the male and female components 120 and 130 arecoupled together, and the piston coupling mechanism 200 can transitionback to the retracted state, in which the piston head 110 is de-coupledfrom the inner walls of the cylinder 400. The effective length of theconnecting rod is now longer than if current had not be activated.

Referring next to FIGS. 6A-C, the engine is operating, and the pistonhead 110 can be positioned at or near bottom dead center (BDC) at stageA—as opposed to TDC at stage A of FIGS. 5A-C. Here, no electric currentis applied to the solenoid 410, and thus the magnetic field proximate tothe cylinder 400 is inactive. That is, there can be no magnetic fieldcapable of moving magnetic bodies in the magnetically-actuated pistonand connecting rod device 100. In such case, the connecting rod devicecan be in the coupled state, and the piston coupling mechanism can be inthe retracted state, as explained above.

At stage B, current can be passed through the solenoid 410, generating amagnetic field along the length of the cylinder 400. This can activatethe connecting rod magnet 150 of the connecting rod device and thepiston coupling mechanism magnet 220 of the piston coupling mechanism200 due to magnetic forces acting in the direction shown by the arrowsthrough solenoid 410. As explained above, activation of the connectingrod magnet 150, whereby the connecting rod magnet 150 moves proximallyalong the axis of the connecting rod, can transition the connecting roddevice to the de-coupled state in which the first and second male-femalecoupling pads 140 release the male component 120, allowing the malecomponent 120 to move independently of the female component 130.Similarly, activation of the piston coupling mechanism magnet 220,whereby the piston coupling mechanism magnet 220 moves down the lengthof the guiding rod 230 in a direction perpendicular to an axis of thepiston coupling mechanism 200 (toward the base member 240), cantransition the piston coupling mechanism 200 to the extended state.Here, the downward movement of the piston coupling mechanism magnet 220can cause the linkage arms 251 and 252 to push the first and secondpiston-cylinder coupling pads 210 along the axis of the piston couplingmechanism 200, in opposite directions, outside of an outer wall of thepiston head 110, such that the first and second piston-cylinder couplingpads 210 abut an inner surface of the cylinder 400 to immobilize or holdthe piston head 110 in place inside of the cylinder 400. Consequently,inertia due to the regular rotational motion of the crankshaft can pushthe male component 120, causing the male component 120 to slidevertically into the female component 130, while the female component 130is prevented from moving vertically due to its connection to the fixedpiston head 110.

At stage C, the current applied to the solenoid 410 can be deactivated.In response, the connecting rod device can transition back to thecoupled state, in which the male and female components 120 and 130 arecoupled together, and the piston coupling mechanism 200 can transitionback to the retracted state, in which the piston head 110 is de-coupledfrom the inner walls of the cylinder 400. The effective length of theconnecting rod is now shorter than if current had not be activated.

The connecting rod device, as described herein, is not limited solely tothe design described herein above. Various modifications to theconnecting rod device are acceptable, as would be appreciated by aperson of ordinary skill in the art, so long as such changes areconsistent with the scope of the accompanying claims.

For example, FIGS. 9A and 9B are views of another exemplarymagnetically-actuated piston and connecting rod device with avariable-length connecting rod. As shown in FIGS. 9A and 9B, themagnetically-actuated piston and connecting rod device 300 can include apiston head 310, which can generally correspond to the piston head 110described hereinabove, coupled to a connecting rod device extendingtherefrom. The piston head 310 can be disposed inside of the cylinder400. While only a single piston and connecting rod device 300 is shownin FIGS. 9A and 9B, the magnetically-actuated piston and connecting roddevice 300 can be disposed in each cylinder 400 of the engine.

The magnetically-actuated piston and connecting rod device 300 canfurther include a connecting rod device coupled to the piston head 310and extending therefrom. Generally similar to the connecting rod deviceof the magnetically-actuated piston and connecting rod device 100described hereinabove, the connecting rod device of themagnetically-actuated piston and connecting rod device 300 can include avariable-length connecting rod with a male component 320 and a femalecomponent 330. The female component 330 can be formed with an at leastpartially hollow body. The male component 320 can be formed such that atleast a portion thereof can be disposed inside of the hollow body of thefemale component 330.

In contrast with the magnetically-actuated piston and connecting roddevice 100, a proximal end of the male component 320 (furthest from thepiston head 310) can be inserted into the female component 330, and adistal end of the male component 320 (closest to the piston head 310)can be coupled to the piston head 310 via the piston coupling mechanism200. (The piston coupling mechanism 200 can operate in the same manneras described hereinabove and thus remain unchanged.) Meanwhile, a distalend of the female component 330 can include an opening configured toreceive the proximal end of the male component 320, and a proximal endof the female component 330 can be formed with a circular openingconfigured to receive the crankshaft (not shown).

Each of the male component 320 and female component 330 can berectangularly shaped in some embodiments, but the respective shapes ofthe male component 320 and female component 330 are not limited thereto.Under certain circumstances as described herein, the female component330 can move back and forth over the male component 320 along the axisof the connecting rod, thereby varying the length of the connecting rod.The male component 320, meanwhile, can remain positionally fixed withrespect to the connecting rod device by virtue of its connection to thepiston head 310.

The connecting rod device can further include a plurality of rollers 340rotatably disposed in or on the male component 320. The rollers 340 canbe wheel-like, i.e., circularly shaped with a circumferential baseportion, and capable of rotation about an axis. The rollers 340 can bedisposed partially inside of the body of the male component 320 suchthat a portion of each roller 340 extends outside of an outer wall ofthe male component 320. As such, an outer surface of one or more of therollers 340 can come into contact with an inner surface of the femalecomponent 330 when a portion of the male component 320 is positionedtherein, allowing the male component 320 to slide within the femalecomponent 330. In some embodiments, the rollers 340 can include one ormore first rollers 340 disposed at a first side of the male component320 and one or more second rollers 340 disposed at a second, oppositeside of the male component 320. While the rollers 340 may be referred toherein in the plural, it is to be understood that the connecting roddevice can include only a single roller 340 in certain embodiments.

The connecting rod device can further include a connecting rod magnet350, which is a magnet movably coupled to the male component 320proximate to the position of the plurality of rollers 340. In someembodiments, the connecting rod magnet 350 can be disposed entirelyinside of the body of the male component 320, as shown in thecross-sectional views of FIGS. 10A-10C and 11A-11C. The connecting rodmagnet 350 can be configured to move along the axis of the connectingrod in response to a magnetic field that is generated proximate to thecylinder 400.

Moreover, under certain circumstances described below, an outer surfacethe connecting rod magnet 350 can come into contact with the respectiveouter surfaces of the rollers 340 in order to prevent rotation thereof.To this end, the connecting rod magnet 350 can be formed with one ormore curved surfaces each of which adjacent to a respective position ofthe rollers 340. The curvature of the connecting rod magnet 350, visiblein FIGS. 10A-10C and 11A-11C, can match or be similar to the curvatureof the rollers 340 to maximize surface contact, i.e., friction, betweenthe connecting rod magnet 350 and the rollers 340.

The connecting rod device can further include springs 351 and 352disposed on opposite axial ends of the connecting rod magnet 350. Forexample, the first spring 351 can be disposed proximally of theconnecting rod magnet 350, and the second spring 352 can be disposeddistally of the connecting rod magnet 350. Proximal movement of theconnecting rod magnet 350 (toward the female component 330) along theaxis of the connecting rod, in response to a magnetic field proximate tothe cylinder 400, can cause the first spring 351 to compress. Upondeactivation of the magnetic field, the first spring 351 can decompressto return the connecting rod magnet 350 to its default or centeredposition. It is to be understood that the springs 351 and 352 are notlimited in their respective amounts. That is, the first spring 351 mayinclude one or multiple first springs, and the second spring 352 mayinclude one or second first springs.

Referring next to FIGS. 10A-10C and FIGS. 11A-11C, the operation of themagnetically-actuated piston and connecting rod device 300 can bedescribed. In detail, the connecting rod device can be configured totransition between a “locked state” and a “unlocked state” (similar tothe aforementioned “coupled” and “de-coupled” states, respectively), asexplained below, in response to a magnetic field proximate to thecylinder 400 in which the magnetically-actuated piston and connectingrod device 300 is disposed. As previously explained, the piston couplingmechanism 200 can be configured to transition between a “retractedstate” and an “extended state,” as explained below, in response to themagnetic field proximate to the cylinder 400 in which themagnetically-actuated piston and connecting rod device 300 is disposed.

As described above, the magnetic field can be generated by wrapping asolenoid 410 (e.g., see FIGS. 5A-C and 6A-C) around each cylinder 400 ofthe engine. When an electric current is applied to the solenoid 410,such that the current passes through the coils of the solenoid 410,magnetic forces act down the length of the cylinder 400, therebygenerating a magnetic field. The magnetic field can cause responsivemovement of magnetic bodies within the magnetic field, such as theconnecting rod magnet 350 or piston coupling mechanism magnet 220, dueto attractive or repulsive magnetic forces acting upon the bodies.

Referring first to FIGS. 10A-10C, which include a cross-sectionalperspective view, a cross-sectional top view, and a cross-sectional sideview, respectively, of the magnetically-actuated piston and connectingrod device 300, no current is applied to the solenoid 410 which iswrapped around cylinder 400. Thus, in the example of 10A-10C, themagnetic field proximate to the cylinder 400 may be inactive, resultingin the locked state of the connecting rod device and the retracted stateof the piston coupling mechanism 200.

Here, the connecting rod magnet 350 can be held in a default or centeredposition by virtue of first and second springs 351 and 352. While theconnecting rod magnet 350 is centered, the rollers 340 can be preventedfrom rotating due to the connecting rod magnet 350 abutting or pressingagainst the outer circumferential surfaces of the rollers 340. As aresult, the male component 320 can be locked in place inside of thefemale component 330 such that the male and female components 320 and330 are held in unison. In this position, the female component 330 isprevented from sliding along the rollers 340, as the rollers 340 areunable to rotate.

Additionally, in the absence of the magnetic field proximate to thecylinder 400, the first and second piston-cylinder coupling pads 210 canbe retracted, or withdrawn, in the piston head 310. That is, the firstand second piston-cylinder coupling pads 210 can be positioned inside ofan outer wall of the piston head 310. In this position, the piston head310 is able to move freely within the cylinder 400 due to regularoperation of the engine.

Next, referring to FIGS. 11A-11C, which include a cross-sectionalperspective view, a cross-sectional top view, and a cross-sectional sideview, of the magnetically-actuated piston and connecting rod device 300,a current passes through the solenoid 410 wrapped around the cylinder400, thereby generating a magnetic field along the length of thecylinder 400. Thus, in the example of FIGS. 11A-11C, the magnetic fieldproximate to the cylinder 400 may be active, resulting in the unlockedstate of the connecting rod device and the extended state of the pistoncoupling mechanism 200.

Here, the connecting rod magnet 350 can move down the length of the malecomponent 320, that is, proximally (toward the female component 330)along the axis of the connecting rod, in response to the generatedmagnetic field, thereby compressing the first spring 351 proximal of theconnecting rod magnet 350. The proximal movement of the connecting rodmagnet 350 can separate the magnet 350 from the rollers 340, allowingthem to rotate. This, in turn, can allow for the inner surface of thefemale component 330 to slide along the rotating rollers 340 such thatthe female component 330 moves freely over the male component 320. By“unlocking” the female component 330, it is allowed to move independentof the male component 320 along the axis of the connecting rod due tothe inertia of the normal crankshaft motion (rotation), therebyadjusting the effective length of the connecting rod. The springs 351and 352 can return the connecting rod magnet 1350 to its centered,“default” position once the current applied to the solenoid 410 stops.

Additionally, in response to the generated magnetic field, the pistoncoupling mechanism 200 can be activated, causing the piston couplingmechanism magnet 220 to move along the guiding rod 230 in a directionperpendicular to the piston coupling mechanism 200 (toward the fixedbase member 240). Such movement of the piston coupling mechanism magnet220 can cause the first and second piston-cylinder coupling pads 210 tomove along the axis of the piston coupling mechanism 200, so as toextend beyond the outer wall of the piston head 310, into the inner wallof the engine cylinder 400. This can hold the piston head 310, and themale component 320 attached thereto, in place inside of the cylinder400.

The unlocking of the female component 330 from the male component 320,along with the coupling of the piston head 310 to the inner wall of thecylinder 400, can enable the female component 330 to freely move overthe male component 320 while current passes through the solenoid 410.Like the magnetically-actuated piston and connecting rod device 100,this can allow for dynamic adjustment of connecting rod length based onthe point in time during the combustion cycle at which the currentactivates, as described in greater detail with reference to FIGS. 12-16.

Next, FIGS. 12-16 demonstrate methods for controlling operation of amagnetically-actuated piston and connecting rod device described herein(e.g., magnetically-actuated piston and connecting rod device 100,magnetically-actuated piston and connecting rod device 300, etc.).Particularly, FIG. 12 is a flowchart 500 illustrating an exemplaryprocedure for controlling operation of a magnetically-actuated pistonand connecting rod device; FIG. 13 includes the flowchart 500 showing anexemplary procedure for lengthening the connecting rod of themagnetically-actuated piston and connecting rod device; FIG. 14 includesthe flowchart 500 showing an exemplary procedure for shortening theconnecting rod of the magnetically-actuated piston and connecting roddevice; FIG. 15 includes the flowchart 500 showing an exemplaryprocedure for lengthening the connecting rod of themagnetically-actuated piston and connecting rod device to achieve atorque increase; and FIG. 16 includes the flowchart 500 showing anexemplary procedure for shortening the connecting rod of themagnetically-actuated piston and connecting rod device after lengtheningthe connecting rod for improved torque.

As shown in FIGS. 12-16, the procedure 500 may start at step 505, andcontinue to step 510, where, as described in greater detail below,operation of the herein-disclosed magnetically-actuated piston andconnecting rod device can be controlled so as to lengthen or shorten thevariable-length connecting rod in response to specific load conditions.For the purpose of FIGS. 12-16, it assumed that themagnetically-actuated piston and connecting rod device is equipped in anengine of a vehicle. However, the magnetically-actuated piston andconnecting rod device described herein is not limited solely tovehicles, but can be equipped in any engine-powered machine.

At step 505, an engine (not shown) can be started, whereby the engineincludes one or more cylinders 400 around which the solenoid 410 iswrapped. It is to be understood that the control logic illustratedthroughout FIGS. 12-16 can be implemented individually for eachmagnetically-actuated piston and connecting rod device disposed in eachcylinder 400 of the engine.

At step 510, a plurality of vehicle measurements can be acquired. Suchvehicle measurements can represent the basis upon which the current loadconditions are determined. In some embodiments, a vehicle controllerarea network (CAN) controller in communication, via an in-vehiclenetwork, with a plurality of sensors disposed throughout the vehicle canacquire the vehicle measurements from individual sensors. For example,such vehicle measurements can include, but are not limited to, anaccelerator or throttle position via an accelerator position sensor(APS), a vehicle speed (VS) via a vehicle speed sensor, a crankshaftposition (CRS_Pos) and a camshaft position (CAM_Pos), a cylinderpressure (Cyl_Press) via a pressure sensor, an engine load percentage(Eng_Load) via an engine load sensor, an effective length of thevariable-length connecting rod (CR_Length) via a proximity sensor, orany combination thereof. It is to be understood that the sensors fordetecting these vehicle measurements are not limited solely to thoselisted above.

Additionally, one or more parameters for controlling the variable-lengthconnecting rod can be managed throughout the procedure 500. For example,activation of the solenoid 410 wrapped around the cylinder 400 can betracked and controlled using ‘SolActive’. SolActive can be a binaryparameter set to either 0 or 1. For example, when no current is appliedto the solenoid 410, such that the magnetic field proximate to thecylinder 400 is deactivated, and magnetic bodies in themagnetically-actuated piston and connecting rod device are in a defaultor centered position, SolActive can be set to 0. Conversely, when acurrent passes through the solenoid 410, such that the magnetic fieldproximate to the cylinder 400 is active, causing movement of themagnetic bodies in the magnetically-actuated piston and connecting roddevice, as described above, SolActive can be set to 1.

At step 515, the vehicle speed and cylinder pressure can be comparedwith predetermined thresholds to determine whether initial conditionsare satisfactory to adjust the variable-length connecting rod. Forexample, the vehicle speed can be compared with a predefined minimumspeed, e.g., 20 kph, and the cylinder pressure can be compared with apredefined maximum pressure, e.g., 2000 kPA.

If the vehicle speed is less than or equal to the predefined minimumspeed or the cylinder pressure is greater than or equal to thepredefined maximum pressure, the procedure 500 can proceed to step 555,whereby the connecting rod device can operate without adjustment, thatis, without lengthening or shortening the connecting rod. Here, theSolActive parameter can be set to 0 to preclude current from passingthrough the solenoid 410. The magnetic field proximate to the cylinder400 can be deactivated as a result. This can cause the connecting roddevice to operate in a manner similar to a conventional fixed-lengthconnecting rod.

Conversely, if the vehicle speed is greater than the predefined minimumspeed and the cylinder pressure is less than the predefined maximumpressure, the procedure 500 can proceed to step 520 and beyond, where itcan be determined whether one or more conditions are satisfied uponwhich the length of the connecting rod can be adjusted by supplyingcurrent to pass through the solenoid 410. Particularly, the loadconditions of the engine can be verified to adjust the connecting rodlength in accordance with the current load, thus improving thecompression ratio and overall driving efficiency. To this end, when lowor high load conditions are experienced, the variable-length connectingrod can be lengthened or shortened by activating the current passingthrough the solenoid 410 at a specific point in time, that is, at apredefined position of the piston in the cylinder 400, e.g., top deadcenter (TDC), bottom dead center (BDC), etc., and a predefinedcombustion stroke of the piston, e.g., exhaust (EXH), intake (INT),compression (COM), etc. Particularly, the engine compression ratio canbe varied to best suit engine load conditions by passing a currentthrough the solenoid 410 during the intake or exhaust stroke, asdescribed below.

It is understood that the length of the connecting rod can be adjustedby supplying a current to pass through the solenoid 410 when one or moreconditions as described herein are satisfied, whereby the one or moreconditions are selected based upon one or more powertrain or vehicleparameters relating to the powertrain and/or vehicle. The one or morepowertrain or vehicle parameters can include, but are not limited to,the current load of the engine, for example.

At step 520, the respective positions of the crankshaft and the camshaftcan be detected in order to confirm the current position of the pistonin the cylinder 400 (i.e., “first condition”) and the current combustionstroke of the piston (i.e., “second condition”). If the position of thecrankshaft indicates that the piston is located at top dead center inthe cylinder 400 (in(CRS_Pos.TDC)==1), i.e., “first position,” and theposition of the camshaft indicates that the combustion stroke of theengine is the exhaust stroke (in(CAM_Pos.EXH)==1), i.e., “first stroke,”the timing can be satisfactory for activating the current passingthrough the solenoid 410 when low load engine conditions are satisfied(step 525). If either of the above conditions are not satisfied,however, the respective positions of the crankshaft and the camshaft canbe re-evaluated at step 530 to confirm the current position of thepiston in the cylinder 400 and the current combustion stroke of thepiston. If the position of the crankshaft indicates that the piston islocated at bottom dead center in the cylinder 400 (in(CRS_Pos.BDC)==1),i.e., “second position,” and the position of the camshaft indicates thatthe combustion stroke of the engine is the intake stroke(in(CAM_Pos.INT)==1), i.e., “second stroke,” the timing can besatisfactory for activating the current passing through the solenoid 410when high load engine conditions are satisfied in (step 535). In someembodiments, a proximity sensor can be used to assess how far the pistonhead 110 is from the top of the cylinder 400 to confirm the piston is attop dead center or the bottom of the cylinder 400 to confirm the pistonis at bottom dead center within approximately +/−5 degrees.

Low or high load engine conditions can be verified in a variety of ways,including comparing the current engine load with a predefined engineload threshold and comparing the current accelerator position with apredefined accelerator position. For example, an accelerator positionthreshold value and engine load threshold value, below which the engineload is low and above which the engine load is high, can be predefined.Using this approach in step 525, if the current accelerator position isless than or equal to a predefined accelerator position threshold value,e.g., 20%, and the current engine load is less than or equal to apredefined engine load threshold value, e.g., 35%, it can be determinedthat low load conditions are present. Conversely, in step 535, if thecurrent accelerator position is greater than the predefined acceleratorposition threshold value, e.g., 20%, and the current engine load isgreater than the predefined engine load threshold value, e.g., 35%, itcan be determined that high load conditions are present.

If the piston is located at top dead center, the combustion stroke ofthe engine is the exhaust stroke, and low engine load conditions areconfirmed, the procedure 500 can proceed to step 545 where it can bedetermined whether the current effective length of the connecting rod isat its maximum. If the effective length of the connecting rod is notalready maximized, the connecting rod can be lengthened by applying anelectric current to the solenoid 410 wrapped around the cylinder 400(SolActive=1) such that the current passes through the solenoid 410 togenerate a magnetic field that activates magnetic bodies of themagnetically-actuated piston and connecting rod device in the mannerdescribed above (step 560). By generating the magnetic field while thepiston is located at top dead center during the exhaust stroke, theconnecting rod can be continuously lengthened as the male component 120is pulled further out of the female component 130, thereby increasingthe effective length of the connecting rod during low load conditions toimprove driving performance, as demonstrated in FIG. 13.

On the other hand, if the piston is located at bottom dead center, thecombustion stroke of the engine is the intake stroke, and high engineload conditions are confirmed, the procedure 500 can proceed to step 545where it can be determined whether the current effective length of theconnecting rod is at its minimum. If the effective length of theconnecting rod is not already minimized, the connecting rod can beshortened by applying an electric current to the solenoid 410 wrappedaround the cylinder 400 (SolActive=1) such that the current passesthrough the solenoid 410 to generate a magnetic field that activatesmagnetic bodies of the magnetically-actuated piston and connecting roddevice in the manner described above (step 560). By generating themagnetic field while the piston is located at bottom dead center duringthe intake stroke, the connecting rod can be continuously shortened asthe male component 120 is pushed further into the female component 130,thereby decreasing the effective length of the connecting rod duringhigh load conditions to improve driving performance, as demonstrated inFIG. 14.

Meanwhile, if the current is passed through the solenoid 410 while thepiston is located at top dead center during the compression stroke, andthe spark timing is delayed until the connecting rod is lengthened (dueto activating the solenoid current while the piston is at top deadcenter), an increased torque on the crankshaft can be produced duringthe power stroke due to the crankshaft being rotated further away fromthe top dead center position when initial power delivery occurs. Indetail, FIG. 15 illustrates a procedure for lengthening thevariable-length connecting rod to improve engine torque. At step 540, itcan be determined whether the crankshaft is positioned such that thepiston is located at top dead center through approximately 30 degreesclockwise (in(CRS_Pos.TT)==1), and the position of the camshaftindicates that the combustion stroke of the engine is the compressionstroke (in(CAM_Pos.COM)==1). If both of the above conditions aresatisfied, the procedure 500 can proceed to step 545 where it can bedetermined whether the current effective length of the connecting rod isat its maximum. If the effective length of the connecting rod is notalready maximized, the connecting rod can be lengthened by supplying thecurrent to the solenoid 410 (SolActive=1) such that the current passesthrough the solenoid 410 to generate a magnetic field that activatesmagnetic bodies of the magnetically-actuated piston and connecting roddevice in the manner described above (step 560). Moreover, the spark canbe delayed until the current passing through the solenoid 410 isdeactivated to produce a higher torque delivery from a larger moment armin the connecting rod device.

FIG. 16 illustrates a shortening for lengthening the variable-lengthconnecting rod to improve engine torque. At step 550, it can bedetermined whether the crankshaft is positioned such that the piston islocated at bottom dead center through approximately 30 degrees clockwise(in(CRS_Pos.TB)==1), and the position of the camshaft indicates that thecombustion stroke of the engine is the exhaust stroke(in(CAM_Pos.EXH)==1). If both of the above conditions are satisfied, theprocedure 500 can proceed to step 545 where it can be determined whetherthe current effective length of the connecting rod is at its minimum. Ifthe effective length of the connecting rod is not already minimized, theconnecting rod can be shortened to return the connecting rod to itsoriginal length (before the compression stroke) by re-supplying thecurrent to the solenoid 410 (SolActive=1) such that the current passesthrough the solenoid 410 to generate a magnetic field that activatesmagnetic bodies of the magnetically-actuated piston and connecting roddevice in the manner described above (step 560). Therefore, theconnecting rod length can continually increase near top dead center ofthe compression stroke, then decrease near bottom dead center of thefollowing exhaust stroke. The adjustment of connecting rod length duringthese times can enable better torque delivery to the crankshaft.

The procedure 500 can continue throughout operation of the engine andend upon deactivation of the engine. The techniques by which the stepsof procedure 500 may be performed, as well as ancillary procedures andparameters, are described in detail above.

It should be noted that the steps shown in FIGS. 12-16 are merelyexamples for illustration, and certain other steps may be included orexcluded as desired. Further, while a particular order of the steps isshown, this ordering is merely illustrative, and any suitablearrangement of the steps may be utilized without departing from thescope of the embodiments herein. Even further, the illustrated steps maybe modified in any suitable manner in accordance with the scope of thepresent claims.

Accordingly, the magnetically-actuated variable-length connecting roddevices and methods for controlling the same discussed herein can yieldpowertrain performance and efficiency improvements by adjusting enginedisplacement to dynamically suit engine load. Under low-load conditions,such as idling, the connecting rod can lengthen, raising the compressionratio and improving efficiency, which results in fuel savings. Underhigh-load conditions, the connecting rod can shorten, lowering thecompression ratio and improving driving performance, such as by allowingincreased boost from a turbocharger with a reduced likelihood of engineknock. Because the variable-length connecting rod device discussedherein is magnetically-actuated, the device can have minimal packagingcompromises compared to conventional variable displacement engineapproaches. For aside from a solenoid wrapped around each enginecylinder, all other components can be contained within the existingengine cylinder space. Moreover, the magnetically-actuatedvariable-length connecting rod device discussed herein can improveenergy efficiency over conventional variable displacement engineapproaches, since only a brief pulse of electric current is sufficientfor actuating the magnetic components that unlock the connecting rodcomponents, as described above, and the connecting rod extends orcontracts using only inertia from the crankshaft.

The foregoing description has been directed to certain embodiments ofthe present disclosure. It will be apparent, however, that othervariations and modifications may be made to the described embodiments,with the attainment of some or all of their advantages. Accordingly,this description is to be taken only by way of example and not tootherwise limit the scope of the embodiments herein. Therefore, it isthe object of the appended claims to cover all such variations andmodifications as come within the true spirit and scope of theembodiments herein.

What is claimed is:
 1. A method comprising: providing a connecting roddevice disposed inside of a cylinder of an engine, the connecting roddevice coupled to a piston head and extending therefrom, the connectingrod device including a variable-length connecting rod and a connectingrod magnet movably coupled to the variable-length connecting rod; andadjusting a length of the connecting rod by supplying a current to passthrough a solenoid wrapped around the cylinder, the current passingthrough the solenoid generating a magnetic field which activates theconnecting rod magnet, wherein the activation of the connecting rodmagnet causes an increase or a decrease of the length of the connectingrod.
 2. The method of claim 1, further comprising: detecting a currentload of the engine using an engine load sensor operatively coupled tothe engine; and adjusting the length of the connecting rod by supplyingthe current to pass through the solenoid when one or more conditions aresatisfied, the one or more conditions selected based on one or morepowertrain or vehicle parameters.
 3. The method of claim 2, wherein theone or more conditions include a first condition characterizing aposition of the piston head in the cylinder and a second conditioncharacterizing a stroke type in the cylinder, and the one or morepowertrain or vehicle parameters include a current load of the engine.4. The method of claim 3, further comprising: detecting the position ofthe piston head in the cylinder by measuring a position of a crankshaftof the engine; and detecting the stroke type in the cylinder bymeasuring a position of a camshaft of the engine.
 5. The method of claim1, further comprising: detecting a current load of the engine using anengine load sensor operatively coupled to the engine; comparing thecurrent load of the engine with a predefined engine load thresholdvalue; determining that high load conditions are present when thecurrent load of the engine is greater than the predefined engine loadthreshold value; and determining that low load conditions are presentwhen the current load of the engine is less than or equal to thepredefined engine load threshold value.
 6. The method of claim 5,further comprising: detecting a current accelerator position using anaccelerator position sensor; comparing the current accelerator positionwith a predefined accelerator position threshold value; determining thatthe high load conditions are present when the current load of the engineis greater than the predefined engine load threshold value and thecurrent accelerator position is greater than the predefined acceleratorposition threshold value; and determining that the low load conditionsare present when the current load of the engine is less than or equal tothe predefined engine load threshold value and the current acceleratorposition is less than or equal to the predefined accelerator positionthreshold value.
 7. The method of claim 5, further comprising: when thehigh load conditions are present, adjusting the length of the connectingrod by supplying the current to pass through the solenoid when thepiston head is at a first position in the cylinder during a first strokein the cylinder; and when the low load conditions are present, adjustingthe length of the connecting rod by supplying the current to passthrough the solenoid when the piston head is at a second position in thecylinder during a second stroke in the cylinder, wherein the firstposition in the cylinder is different from the second position in thecylinder, and the first stroke is different from the second stroke. 8.The method of claim 5, further comprising: when the low load conditionsare present, adjusting the length of the connecting rod by supplying thecurrent to pass through the solenoid when the piston head is at a topdead center position in the cylinder during an exhaust stroke in thecylinder.
 9. The method of claim 8, wherein the current passing throughthe solenoid when the piston head is at the top dead center position inthe cylinder during the exhaust stroke in the cylinder generates amagnetic field which activates the connecting rod magnet such that thelength of the connecting rod increases.
 10. The method of claim 5,further comprising: when the high load conditions are present, adjustingthe length of the connecting rod by supplying the current to passthrough the solenoid when the piston head is at a bottom dead centerposition in the cylinder during an intake stroke in the cylinder. 11.The method of claim 10, wherein the current passing through the solenoidwhen the piston head is at the bottom dead center position in thecylinder during the intake stroke in the cylinder generates a magneticfield which activates the connecting rod magnet such that the length ofthe connecting rod decreases.
 12. The method of claim 1, furthercomprising: acquiring a plurality of measurements characterizing anoperation of the engine using one or more sensors; determining whetherto adjust the length of the connecting rod by supplying the current topass through the solenoid based on one or more of the plurality ofmeasurements.
 13. The method of claim 1, further comprising: detecting avehicle speed using a vehicle speed sensor; detecting a cylinderpressure of the cylinder using a pressure sensor; and adjusting thelength of the connecting rod by supplying the current to pass throughthe solenoid when the vehicle speed is greater than a predefined minimumspeed and the cylinder pressure is less than a predefined maximumpressure.
 14. The method of claim 1, further comprising: adjusting thelength of the connecting rod by supplying the current to pass throughthe solenoid when the piston head is at a top dead center position inthe cylinder during a compression stroke in the cylinder, whichgenerates a magnetic field that activates the connecting rod magnet suchthat the length of the connecting rod increases.
 15. The method of claim14, further comprising: after supplying the current to pass through thesolenoid when the piston head is at the top dead center position in thecylinder during the compression stroke in the cylinder, deactivating thecurrent passing through the solenoid, after which a spark is generatedin the cylinder.
 16. The method of claim 15, further comprising: afterdeactivating the current passing through the solenoid, adjusting thelength of the connecting rod by re-supplying the current to pass throughthe solenoid when the piston head is at a bottom dead center position inthe cylinder during an exhaust stroke in the cylinder, which generates amagnetic field that activates the connecting rod magnet such that thelength of the connecting rod decreases.
 17. A method comprising:providing a connecting rod device disposed inside of a cylinder of anengine, the connecting rod device coupled to a piston head and extendingtherefrom, the connecting rod device including a variable-lengthconnecting rod including a female component with a hollow body and amale component movably disposed at least partially inside of the femalecomponent, the male component configured to be coupled to a crankshaftof the engine, and the connecting rod device further including aconnecting rod magnet movably coupled to the female component; andsupplying a current to pass through a solenoid wrapped around thecylinder, the current passing through the solenoid generating a magneticfield which activates the connecting rod magnet, wherein the activationof the connecting rod magnet causes the connecting rod device totransition from a coupled state, in which the male component is held inunison with the female component, to a de-coupled state, in whichmovement of the connecting rod magnet causes a release of the malecomponent, allowing the male component to move independent of the femalecomponent along an axis of the connecting rod.
 18. The method of claim17, further comprising: deactivating the current passing through thesolenoid causing the connecting rod device to transition back to thecoupled state from the de-coupled state.
 19. A method comprising:providing a connecting rod device disposed inside of a cylinder of anengine, the connecting rod device coupled to a piston head via a pistoncoupling mechanism disposed at least partially inside of the pistonhead, the connecting rod device including a variable-length connectingrod, the piston coupling mechanism including first and secondpiston-cylinder coupling pads movably disposed at opposite axial ends ofthe piston coupling mechanism, respectively, and a piston couplingmechanism magnet movably disposed at least partially between the firstand second piston-cylinder coupling pads; and supplying a current topass through a solenoid wrapped around the cylinder, the current passingthrough the solenoid generating a magnetic field which activates thepiston coupling mechanism magnet, wherein the activation of the pistoncoupling mechanism magnet causes the piston coupling mechanism totransition from a retracted state, in which the first and secondpiston-cylinder coupling pads are positioned inside of an outer wall ofthe piston head, to an extended state, in which movement of the pistoncoupling mechanism magnet causes the first and second piston-cylindercoupling pads to move along an axis of the piston coupling mechanismoutside of the outer wall of the piston head, such that the first andsecond piston-cylinder coupling pads abut an inner surface of thecylinder to hold the piston head in place inside of the cylinder. 20.The method of claim 19, further comprising: deactivating the currentpassing through the solenoid causing the piston coupling mechanism totransition back to the retracted state from the extended state.